body{
    font-size: 20px;
    font-family: "微软雅黑";
    color:blue;

}
.box1{
   
        border: 1px solid #000;
        padding: 5px;
    }
    .box2{
        
        background-color: #999;
        color:red;
    }
    #box21{
        float:left;
    }
    #box22{
        float:left;
    }
    #box23{
        float:left;
    }
    .clear{
        clear:both;
    }